You may have some success with freight forwarders such as TransGroup or Ocean Air. You may find it doesn't add a great deal of cost to use a forwarder, and may still be cheaper than USPS.

Not sure about the difficulties of shipping as an individual instead of a corporation, but the freight forwarder is motivated to find a solution for you. Perhaps using your SSN as the Business Tax ID and identifying as a Sole Proprietor would be sufficient.

Also, try Aloha Freight if speed is not an issue. I think ocean freight takes about a week.

Lastly, look at Aloha Air Cargo. For your shipment, rates come out around $450. You do need to be a known shipper, but the application looks simple and straightforward. 5 business days to process the app, though.